Water pump or crank pulley - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Bala · 10-25-2012, 06:42 AM

I have a typical water pump bearing/pulley kind of noise. It is affected by change in RPM. I removed the belt and it is still tied to RPM. I use a hose to my ear and it seems to be coming just around the crank pulley but not 100% sure. Any ideas whether it could be the water pump? I'm not sure if it still is the original pump and the car has 92k miles. I'm swapping the engine mount and would liek to get this addressed if it is water pump, at the same time.

Meir · 10-25-2012, 06:59 AM

Quote:

Originally Posted by Bala

I have a typical water pump bearing/pulley kind of noise. It is affected by change in RPM. I removed the belt and it is still tied to RPM. I use a hose to my ear and it seems to be coming just around the crank pulley but not 100% sure. Any ideas whether it could be the water pump? I'm not sure if it still is the original pump and the car has 92k miles. I'm swapping the engine mount and would liek to get this addressed if it is water pump, at the same time.

hi Bala.
if you removed the belt, and started the engine without it, it cannot be the pump.
if the pump is not spinning, it cannot be the cause of the noise.

Eric G · 10-25-2012, 07:53 AM

Power steering comes to mind or idler pully...

(have you checked if you have loose spark plugs...you know I had to say it).

Bala · 10-25-2012, 08:05 AM

@Meir,
Thanks for confirming. I think my brain is losing its logical troubleshooting capability.

@Eric,
I read a few posts that pointed to PS and spark plug. I topped off the PS fluid and it took very little. So, maybe the PS pump (?) is target? I did have to tighten the plug for cyl 5 some time ago. So, going to recheck that as well. But, the noise is coming from just about where the crank pulley (the one we use to put TDC) and I'm not able to nail it down. I shall make a video/audio and post. Maybe that'll shed more light on this.

thstone · 10-25-2012, 12:10 PM

Quote:

Originally Posted by Bala

I have a typical water pump bearing/pulley kind of noise. It is affected by change in RPM. I removed the belt and it is still tied to RPM. I use a hose to my ear and it seems to be coming just around the crank pulley but not 100% sure. Any ideas whether it could be the water pump? I'm not sure if it still is the original pump and the car has 92k miles. I'm swapping the engine mount and would liek to get this addressed if it is water pump, at the same time.

If you removed the belt, then the water pump, a/c compressor, power steering pump, idler pulley, and tensioner pulley are all ruled out because they all run off of the belt.

Bala · 10-25-2012, 12:29 PM

Then I'm close to the source I guess. The crank pully?

Steve Tinker · 10-25-2012, 02:52 PM

The crank pulley is just that - a pulley bolted directly onto the crankshaft, so IF you've pinned down the noise correctly, its the crank main bearings or end float thats making the noise.

I think I read somewhere that if you push the clutch in and the noise goes away it could possibly be exessive crankshaft end float.....

Bala · 10-26-2012, 05:20 AM

I'm going to get busy this weekend. Thanks for the advice guys.

Meir · 10-26-2012, 07:25 AM

hi bala.
i was trying to think what could be the source of the noise, when the belt is off.
hope for you that nothing is wrong with the crankshaft bearing.
the only two moving parts in that area (as far as i know), are the oil pump (red arrow), and the scavenge pump (yellow).
see if you could narrow down the source of the noise to one of them.
this is just an assumption, and i don't want to misleads you.
hope you will end up finding it to be something simple to fix.
good luck.

talvez · 01-09-2014, 03:26 PM

Quote:

Originally Posted by Steve Tinker

The crank pulley is just that - a pulley bolted directly onto the crankshaft, so IF you've pinned down the noise correctly, its the crank main bearings or end float thats making the noise.

Id like to know more about what the causes of a noisy crank pulley can be. Is there any other ways the pulley would be making noises? Im also having noise come from the crank pulley.

A floating crank end or bad main bearings is not what I need right now.... Would a bad end float cause a leak to form behind the pulley?

thanks you guys

Benjamin · 04-17-2014, 03:15 AM

Quote:

Originally Posted by talvez

Would a bad end float cause a leak to form behind the pulley?

I'm assuming you're getting an oil leak from there and that's why you are asking.

There is an oil seal there and excessive end float shouldn't cause it to leak, because "end float", as I define it, is excessive movement of the crank moving in and out, along the axis of the crank. The seal should continue to to work in this case. A bad bearing would lead to run out, in which the pulley end would move side to side. This could potentially lead to the seal leaking. Or the seal could just be old and tired and leaking or some debris from the inside has compromised it.

Bala · 10-26-2012, 08:03 AM

Meir,
Thank you. I hope so and I'm sure I will with all the help here. This morning I noticed the noise went away when the engine got hot. I had just changed my trans oil to Porsche but know that it has nothing to do with it. Next is the mount. So, going to take all these advice and hopefully I can identify it.

Meir · 10-26-2012, 08:23 AM

ooopsss..
i forgot to attach the picture.
just in case.

Meir · 10-26-2012, 08:34 AM

also make sure you don't have a funky dude with a blue shirt, hiding behind bank 1, and making funny noises

(just to cheer you up)

seventythree · 10-26-2012, 09:46 AM

Quote:

Originally Posted by Bala

Meir,
Thank you. I hope so and I'm sure I will with all the help here. This morning I noticed the noise went away when the engine got hot. I had just changed my trans oil to Porsche but know that it has nothing to do with it. Next is the mount. So, going to take all these advice and hopefully I can identify it.

Bala, if you're talking about a little buzzing sound that is present for a couple of minutes when you cold start the engine, that would be a noisy secondary air pump. I wouldn't worry about it.

Meir · 10-26-2012, 11:55 AM

Quote:

Originally Posted by seventythree

Bala, if you're talking about a little buzzing sound that is present for a couple of minutes when you cold start the engine, that would be a noisy secondary air pump. I wouldn't worry about it.

+1
didn't think about that.
the secondary air pump will sound like a blower, and will work for X minutes when the engine is cold.
on the other hand, you should be familiar with that sound long time ago.
you have your car for what, year and a half now?
maybe it will be a good idea to post a video/audio clip before you take the car apart.

Bala · 10-26-2012, 12:35 PM

I know what you guys are talking about and I'm used to it now. In fact I worry if I dont hear it.

This is really a water pump like sound. I'll post a recording tonight.

Homeboy981 · 10-27-2012, 04:48 AM

But again, it IS NOT making noise without the belt, right?

That would eliminate the water pump wouldn't it?

Can chain tensioners cause that noise?

Bala · 10-28-2012, 04:26 AM

Quote:

Originally Posted by Homeboy981

But again, it IS NOT making noise without the belt, right?

That would eliminate the water pump wouldn't it?

Can chain tensioners cause that noise?

Withy the belt off it is still there. Tried a little wd40 but no help. Still trying to troubleshoot as per advice above. Spent the whole day on engine mount. That darn bolt on the back.... Had to to remove coolant pipes.

srad34 · 10-28-2012, 04:32 AM

The front mount should only make a clunking noise on the go if its worn/split, not whilst parked. Engine mount is a 2 hour job with ramps. Pedros removal guide is spot on too.

I agree, a video clip might help eliviate or confirm your concerns....